fluorescent tubes...and their manipulation

[rogeryermaw]

ok so this may be more of a tool issue than a chemistry one but it is to make a tool for a chemical process. i have spoken some about the synthesis of hexachlorobenzene (HCB) and i'm finally ready to get it moving. i have everything i need except benzene but it is easy to order so no worry there but i am dissatisied with the borosilicate tubing i have been able to source. i have shopped for fused quartz tubing but it is pretty expensive so i mulled it over then it hit me! fluorescent tubes are cheap, plentiful and made of fused quartz! but..... how to clean it? i need to remove the phosphor coating and mercury before i can use it. any tips or processes anyone here has tried with success?

 

also any advice for cutting it cleanly would be very appreciated.

[Arthur]

I'd want proof of the type of glass before designing a cleaning process and using it in critical processes.

 

Blowtorch and infrared thermometer seems like a crude test, see what temperature the tube starts to deform. Check against figures for soda glass and fused silica.

[robbo]

The fused quartz fluorescent tubes you may be thinking of are germicidal UV-transmitting lights without fluors coating their inner surfaces. They are made with a specialty quartz glass (not cheap stuff) to be as transparent as possible to the very short wavelength UV radiation that's lethal, hence their germicidal properties. Regular fluorescent lights don't need such expensive glass; they are coated inside with fluors to intercept the nasty hard UV from the mercury emissions and re-emit light at longer, visible wavelengths. The last thing desired in a regular fluorescent bulb is lots of UV getting through, although it does occur to some extent. A mixture of specific fluors gives the different "color spectrum"/"color temp" properties we consumers desire..

 

I kind of doubt that regular tubes are made with such a specialty glass, since they're not intended to be UV transparent. They may be pure Si and O (i.e., quartz) unlike our regular glass and borosilicate, I just don't see why. But still, they are so thin as to be nearly useless for practical chemistry. But if you're doing photochemistry, the quartz may be required.

 

Beware, though: doing nasty chemistry on the cheap is a good way to demo natural selection...

[rogeryermaw]

I guess patience is a virtue in this case. The tube i need from an actual fused quartz supplier will run between 80 to maybe 110 dollars and i haven't really cheaped out on anything else for this process yet so why start now? Thanks for the info and advice.

[robbo]

Not to deter you from your endeavor, but there are plenty of decent substitutes for HCB that work for great blues and decent colored non AP strobes. Some formulas are published, some formulas just need tinkering around with various Cl donors. I've got a fair weight of HCB and calomel left over from the 70s and 80s, when they were common, and rarely play with them.

[rogeryermaw]

i have only used hcb a couple of times but i was impressed with the results. one factor important to me is that it burns much cleaner than parlon and doesn't leave that cinder trail muddying color effects with b.b. radiation. besides, i've already invested in the rest of the equipment and chemicals needed to run this.

 

as projected, what i've priced so far is definitely in the 80 dollar plus range. anyone here use a glass supplier in the u.s. they trust that handles material like this?

[MadMat]

Unless you actually need uv transparent tubing, I wouldn't bother with fused quartz, simply because of the price. In the past, I played around with lasers a lot and obtained some supplies from a shop that did custom neon lighting. These supplies included glass tubing of various compositions (most was simply fused silica, but they had borosilicate and even fused quartz as well) and diameters. When I told the owner that I wanted the supplies for laser experiments, he was very interested and sold me everything for VERY cheap. Just a thought.

Edited February 20, 2018 by MadMat

[rogeryermaw]

excellent thought but can you name your supplier? by p.m. if you don't wish to name names?

Edited February 21, 2018 by rogeryermaw

[MadMat]

This was in the 1990's, in Milwaukee Wi. and the company has since either moved, merged or dissolved. But, if I were you, I would check around your area for a local company that makes neon signs. You need to call around to get a "feel" for the company. I did the same for companies that built custom circuit boards and found one that was willing to sell me some double sided, copper clad pc board. You can even try the old "my son/daughter is needs this for a science fair project" bit. You would be surprised how even unfriendly companies soften up when you tell them that.

Edited February 21, 2018 by MadMat

[rogeryermaw]

koo thanks for the tip! i'll give it a try

[tenneyguy]

The fused quartz fluorescent tubes you may be thinking of are germicidal UV-transmitting lights without fluors coating their inner surfaces. They are made with a specialty quartz glass (not cheap stuff) to be as transparent as possible to the very short wavelength UV radiation that's lethal, hence their germicidal properties. Regular fluorescent lights don't need such expensive glass; they are coated inside with fluors to intercept the nasty hard UV from the mercury emissions and re-emit light at longer, visible wavelengths. The last thing desired in a regular fluorescent bulb is lots of UV getting through, although it does occur to some extent. A mixture of specific fluors gives the different "color spectrum"/"color temp" properties we consumers desire..

 

I kind of doubt that regular tubes are made with such a specialty glass, since they're not intended to be UV transparent. They may be pure Si and O (i.e., quartz) unlike our regular glass and borosilicate, I just don't see why. But still, they are so thin as to be nearly useless for practical chemistry. But if you're doing photochemistry, the quartz may be required.

 

Beware, though: doing nasty chemistry on the cheap is a good way to demo natural selection...

When I was a kid, they sold a type of "glass" called "Vitaglass", which was basically transparent to UV, where common glass was not. Used in germicidal lamps, folks bought those to put in their infants' rooms! I searched the name awhile back, came up with nothing.

[NeighborJ]

http://www.greatglas.com/SightGlassRedline.htm

I've used sight glass tubing in the HVAC industry. This site may offer what you want. It's used in chemical storage tanks and boiler expansion tanks. The price isn't too bad.